The 27 bands it covers and helpful search functions on it made me buy it. You can try and get it off e-bay. I bought mine for $315 when it was first released. It has been the best scanner I have EVER used. One of the best purchases I've ever made in my life. Welll worth it.

It has continous band coverage from 25MHz to 1.3 GHz (excluding the cell phone band in the 900's to 1200's) There are also many adapters and accesories for the scanner, like an extension head, AM radio adapter, its PC connectable with a serial cable...etc

If you have a airband transceiver, and you are sitting in your house, are you allowed to chit-chat with pilots flying overhead? and can you give them current weather conditions at your house if you have a little home weather station thing set up? or is this all illegal based on FAA rules?

This is strongly discouraged. I can't find an explicit guideline in the AIM prohibiting it, but the frequency (CTAF) is really reserved (in practice) for aircraft arriving and departing the airport. Of course, it goes without saying that you should never transmit on a frequency used by any ATC facility.

Regarding chatting on a US-based air frequency, you won't find information about unauthorized parties using the air frequencies in the AIM because the AIM is not regulatory. The FAR (Federal Aviation Regulations) is the document that is regulatory but it only deals with "authorized parties."

Using a handheld transmitter to speak on frequencies designated as air frequencies without an authorized aircraft or ground-based station ID is a violation of FCC (the US govt branch responsible for the frequencies) regulations and fines and penalties are pretty stiff.

I believe that ground-based stations, such as FBOs, who need to broadcast on an air frequency must apply for a radio license with the FCC. Pilots who use hand-helds to broadcast from the ground (as in to receive a clearance before aircraft start) are authorized by virtue of their aircraft ID.

To the person who pointed out that there is a lot of chit-chat on air frequencies, you are certainly right. However, keep in mind that both parties doing the chatting are identifiable by a station ID. If it were determined that the chat violated some FCC regulation, they would be identified by their station ID and prosecuted.

To tell you the truth, I do not use the Trunk Tracking. My Uncle bought his 785D because he wanted to have the Digital Trunking and moniter the CT state police. Technology is always improving though. It depends how you want to use the scanner. If you are going to use it for mostly VHF/UHF it's worth while to get the 780XLT, while if you want the Digital Trunk Tracking capability, the 785D might be your choice.

The 785XLT also has TV band search in the search mode. I can mute my TV and tune into channel 4 for the audio

You may only use your hand-held aircraft VHF radio from your aircraft, or under the authority of an FCC ground station authorization. Ground station authorizations are usually only issued to aviation service organizations located on airports, businesses engaged in pilot training, aircraft manufacturers, or persons engaged in chase-car activities related to soaring and ballooning.